Address mapping tables are used to store logical-to-physical storage address translation information. For example, solid-state drives (SSDs) that implement flash memory typically store new and updated data corresponding to write operations at physical addresses that do not directly correlate to logical addresses provided by the host operating system. As a result, the logical addresses from the host operating system are conventionally mapped to physical memory cell locations in the SSD and stored in an address mapping table.
Address mapping tables may be used in other types of storage devices, as well. For example, shingled magnetic recording (SMR) hard disk drives (HDDs) typically require that write data be sequentially written to physical addresses in the chronological order of the write operations. Thus, the logical addresses may be mapped to corresponding physical addresses in the SMR HDD and stored in an address mapping table.
In some existing data storage devices, logical-to-physical (L2P) address mapping tables are stored in relatively low-latency memory to provide quick access to the address mapping tables while the storage device is in operation. As storage media capacity has increased, the required amount of high-speed memory in these storage devices has grown proportionately.
At the same time, the storage density of conventional high-speed memory has increased at a lower rate than the rate of increase in storage density of typical storage devices. In particular, larger amounts of high-speed memory commonly require increased dedicated printed circuit board assembly (PCBA) space. In addition, larger amounts of high-speed memory typically consume more power. Moreover, high-speed memory generally is relatively costly.
Some existing solutions have involved moving segments of the address mapping table between the storage media and relatively fast memory during operation. While this sort of paging scheme may reduce the required amount of high-speed memory in the device, it has an undesirable effect on performance and power consumption.